Covid Arm is a delayed skin reaction that occurs at the injection site of the Moderna or Pfizer COVID-19 vaccines, usually appearing a week after the first or second dose. Symptoms include injection site pain, swelling, itching and rashes. While uncommon, Covid Arm is considered benign and resolves on its own with no serious health effects. The article discusses the signs, symptoms and remedies associated with Covid Arm, noting it is primarily linked to the Moderna vaccine through delayed hypersensitivity of the skin.